Spindle motor and hard disk drive including the same

A spindle motor comprising:

• a sleeve fixedly installed on a base member and having a circulation hole formed in an axial direction;
• a shaft rotatably inserted into the sleeve;
• a rotor hub fixedly installed on an upper end portion of the shaft in the axial direction;
• and
• a thrust member installed in an installation groove formed in an upper portion of the sleeve in the axial direction and forming a connection part at the time of being installed in the installation groove, the connection part allowing the circulation hole to be in communication with a sealing part formed by the sleeve and the rotor hub and having a liquid-vapor interface of a lubricating fluid disposed therein,
• wherein the connection part is formed between the sleeve and the thrust member in a circumferential direction, and at least any one part of a radial outer portion of the connection part has an axial gap smaller than that of another part thereof in the circumferential direction.